Vol. XXvi] ENTOMOLOGICAL NEWS 6l 



At this time, the remaining bright orange female was 

 found mating. 



9 a. m., July 20. The orange of the female which was 

 seen mating on the previous afternoon had changed to dark 

 brown on the thorax and head, but a little orange was still 

 visible on the sides of segments i and 2. The remainder of 

 the dorsum was dull grayish blue and there was a band on the 

 apex of segments I to 7 and the posterior half of 8, while all of 

 segments 9 and 10 were blackish. The face, sides of the thorax 

 and the underparts were greenish yellow. 



The two pruinose females were slightly darker in color, 

 the apex of the blackish triangle on 8 having almost reached 

 the basal border of the segment. These three individuals were 

 placed in a smaller cage of wire gauze. 



Six orange females which had emerged in the laboratory 

 on July 19 and 20 were now placed in the large cage and no 

 males included. 



9. a. m., July 24. No change occurred until this date, when 

 one orange female became slightly pruinose with a tinge of 

 brown on the abdomen. 



July 25. Two other females had become pruinose, and in 

 lime these and the one observed July 24 assumed a colora- 

 tion like the one first described. No further change was noted 

 in those which had been placed in the small cage except that 

 they became more pruinose. 



From these data we may conclude that the female of 

 Ischnura verticalis Say varies some\vhat in size and at the 

 time of emergence is marked with bright orange on the post- 

 ocular spots, the thorax and the first three segments of the 

 abdomen. Four days or more after emergence, this orange 

 turns to brown and then to a gray blue. At the same time the 

 bronze black becomes bluish or blackish. The face, sides of 

 the thorax and the underparts become yellowish green. This 

 entire color change may take place in less than eighteen hours, 

 and may occur either before or after mating. The rapidity 

 with which the color changes occurred after mating in the 



